U.S. patent application number 13/305957 was filed with the patent office on 2012-05-31 for optical device and manufacturing method therefor.
This patent application is currently assigned to NIDEC SANKYO CORPORATION. Invention is credited to Akira MORI, Shinichi NIWA, Hiromitsu TAKEI, Masao TAKEMURA.
Application Number | 20120134034 13/305957 |
Document ID | / |
Family ID | 46126493 |
Filed Date | 2012-05-31 |
United States Patent
Application |
20120134034 |
Kind Code |
A1 |
NIWA; Shinichi ; et
al. |
May 31, 2012 |
OPTICAL DEVICE AND MANUFACTURING METHOD THEREFOR
Abstract
An optical device may include a movable body holding a lens, a
fixed body movably holding the movable body, a drive magnet and a
drive coil for relatively moving the movable body with respect to
the fixed body, and a metal member fixed to the drive magnet. The
drive magnet is fixed to one of the movable body and the fixed body
and the drive coil is fixed to the other of the movable body and
the fixed body. A nickel plating layer containing at least nickel
is formed on a surface of the drive magnet and a surface of the
metal member, and the drive magnet and the metal member are joined
to each other by a joining layer which is made of tin-based metal
containing at least tin and is disposed between the drive magnet
and the metal member.
Inventors: |
NIWA; Shinichi; (Nagano,
JP) ; TAKEMURA; Masao; (Nagano, JP) ; TAKEI;
Hiromitsu; (Nagano, JP) ; MORI; Akira;
(Nagano, JP) |
Assignee: |
NIDEC SANKYO CORPORATION
Nagano
JP
|
Family ID: |
46126493 |
Appl. No.: |
13/305957 |
Filed: |
November 29, 2011 |
Current U.S.
Class: |
359/824 ;
219/602; 228/159; 228/203 |
Current CPC
Class: |
G02B 13/001 20130101;
H02K 41/0356 20130101; G02B 7/023 20130101; G02B 7/102
20130101 |
Class at
Publication: |
359/824 ;
228/203; 228/159; 219/602 |
International
Class: |
G02B 7/02 20060101
G02B007/02; B23K 31/02 20060101 B23K031/02; H05B 6/10 20060101
H05B006/10; B23K 20/24 20060101 B23K020/24 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 30, 2010 |
JP |
2010-266749 |
Claims
1. An optical device comprising: a movable body which holds a lens
for photography; a fixed body which movably holds the movable body;
a drive magnet and a drive coil for relatively moving the movable
body with respect to the fixed body; and a metal member which is
fixed to the drive magnet; wherein the drive magnet is fixed to one
of the movable body and the fixed body, and the drive coil is fixed
to the other of the movable body and the fixed body, and the drive
magnet and the drive coil are oppositely disposed to each other
through a predetermined gap space; wherein a nickel plating layer
containing at least nickel is formed on a surface of the drive
magnet and a surface of the metal member, and wherein the drive
magnet and the metal member are joined to each other by a joining
layer which is made of tin-based metal containing at least tin and
is disposed between the drive magnet and the metal member.
2. The optical device according to claim 1, wherein a tin plating
layer which covers the nickel plating layer is formed on the
surface of the drive magnet before the metal member is joined to
the drive magnet, and the joining layer is formed by melting and
solidifying the tin plating layer at a time of joining of the drive
magnet to the metal member.
3. The optical device according to claim 2, wherein the tin plating
layer is melted by induction heating at a time of joining of the
drive magnet to the metal member.
4. The optical device according to claim 3, wherein the metal
member is fixed to an end face of the drive magnet in an optical
axis direction of the lens, and the drive magnet and the drive coil
are oppositely disposed to each other through a predetermined gap
space in a direction perpendicular to the optical axis direction of
the lens.
5. The optical device according to claim 4, wherein at least a part
of the joining layer and the drive coil are oppositely disposed to
each other through a predetermined gap space.
6. The optical device according to claim 2, wherein the metal
member is comprised of a first metal member and a second metal
member which are fixed to the drive magnet in a state that the
drive magnet is sandwiched by the first metal member and the second
metal member.
7. The optical device according to claim 6, wherein the first metal
member is comprised of one piece of the first metal member, the
second metal member is comprised of a plurality of the second metal
members, the drive magnet is comprised of a plurality of the drive
magnets, each of the plurality of the second metal members is fixed
to each of the plurality of the drive magnets, and each of the
plurality of the second metal member is formed by removing a
connecting member for connecting the plurality of the second metal
members with each other.
8. The optical device according to claim 1, wherein the metal
member is fixed to an end face of the drive magnet in an optical
axis direction of the lens, and the drive magnet and the drive coil
are oppositely disposed to each other through a predetermined gap
space in a direction perpendicular to the optical axis direction of
the lens.
9. The optical device according to claim 8, wherein at least a part
of the joining layer and the drive coil are oppositely disposed to
each other through a predetermined gap space.
10. The optical device according to claim 8, wherein the metal
member is comprised of a first metal member and a second metal
member which are fixed to the drive magnet in a state that the
first metal member and the second metal member sandwich the drive
magnet.
11. The optical device according to claim 10, wherein the first
metal member is comprised of one piece of the first metal member,
the second metal member is comprised of a plurality of the second
metal members, the drive magnet is comprised of a plurality of the
drive magnets, each of the plurality of the second metal members is
fixed to each of the plurality of the drive magnets, and each of
the plurality of the second metal members is formed with a removing
trace which is formed when a connecting member for connecting the
plurality of the second metal members with each other is
removed.
12. The optical device according to claim 11, wherein the removing
trace is formed at a tip end of a protruded part whose base end
part is connected with the second metal member, and a width of the
removing trace is narrower than a width of the base end part of the
protruded part and/or a thickness of the removing trace is thinner
than a thickness of the base end part of the protruded part.
13. The optical device according to claim 1, wherein the movable
body is held by the fixed body movably in the optical axis
direction of the lens, the drive coil is fixed to the movable body,
the drive magnet is fixed to the fixed body, and the drive coil and
the drive magnet relatively move the movable body in the optical
axis direction with respect to the fixed body.
14. The optical device according to claim 13, wherein the drive
magnet is formed in a substantially columnar shape or a
substantially flat plate shape and is magnetized so that a magnetic
pole of one face and a magnetic pole of the other face in the
optical axis direction are different from each other, the drive
coil is oppositely disposed to a side face of the drive magnet in a
direction perpendicular to the optical axis direction through a
predetermined gap space so as to cover a part of the side face of
the drive magnet, and the metal member is fixed to each of both
sides of the drive magnet in the optical axis direction.
15. The optical device according to claim 14, wherein the metal
member which is fixed to one face of the drive magnet in the
optical axis direction is a cover member structuring an outer
peripheral face of the optical device, and the cover member is
formed to cover the metal member which is fixed to the other face
of the drive magnet in the optical axis direction.
16. The optical device according to claim 1, wherein the movable
body is swingably held by the fixed body so that an optical axis of
the lens is inclined, the drive coil is fixed to the fixed body,
the drive magnet is fixed to the movable body, and the movable body
is swung by the drive coil and the drive magnet with respect to the
fixed body.
17. The optical device according to claim 16, wherein the drive
magnet is formed in a substantially flat plate shape and is
magnetized so that a magnetic pole of one side face and a magnetic
pole of the other side face in a direction perpendicular to the
optical axis direction are different from each other, the drive
coil is oppositely disposed to a side face of the drive magnet in a
direction perpendicular to the optical axis direction through a
predetermined gap space, and the metal member is fixed to each of
both end faces of the drive magnet in the optical axis
direction.
18. The optical device according to claim 17, wherein the drive
magnet is comprised of a plurality of drive magnets, the drive coil
is comprised of a plurality of drive coils, the plurality of the
drive magnets is fixed to an outer peripheral face of the movable
body, the fixed body is provided with a case body which is formed
in a substantially tube-like shape and structures an outer
peripheral face of the optical device, the plurality of the drive
coils is fixed to an inner peripheral face of the case body so as
to respectively face the plurality of the drive magnets, and the
plurality of the drive magnets is connected by the metal
member.
19. A manufacturing method for an optical device provided with a
movable body which holds a lens for photography, a fixed body which
movably holds the movable body, a drive magnet and a drive coil for
relatively moving the movable body with respect to the fixed body,
and a metal member which is fixed to the drive magnet and, in the
optical device, the drive magnet is fixed to one of the movable
body and the fixed body, and the drive coil is fixed to the other
of the movable body and the fixed body, and the drive magnet and
the drive coil are oppositely disposed to each other through a
predetermined gap space, the manufacturing method comprising:
forming a nickel plating layer containing at least nickel on a
surface of the drive magnet and a surface of the metal member;
forming a tin plating layer which is made of tin-based metal
containing at least tin on the surface of the drive magnet before
the metal member is joined so as to cover the nickel plating layer;
and melting and solidifying the tin plating layer to join the drive
magnet and the metal member to each other at a time of joining of
the drive magnet to the metal member.
20. The manufacturing method for an optical device according to
claim 19, wherein the tin plating layer is melted by heating when
the drive magnet and the metal member are held in a pressurized
state.
21. The manufacturing method for an optical device according to
claim 20, wherein the tin plating layer is melted by induction
heating at a time of joining of the drive magnet to the metal
member.
22. The manufacturing method for an optical device according to
claim 20, wherein the drive magnet before joined to the metal
member is in a non-magnetized state, and the drive magnet is
magnetized after the drive magnet and the metal member have been
joined to each other.
23. The manufacturing method for an optical device according to
claim 19, wherein the drive magnet is comprised of a plurality of
the drive magnets, the metal member is comprised of a plurality of
the metal members which is fixed to each of the plurality of the
drive magnets, and each of the plurality of the metal members is
formed so that, after the plurality of the drive magnets and the
plurality of the metal members are joined to each other in a state
that the plurality of the metal members are connected with each
other through a connecting member, the connecting member is
removed.
24. The manufacturing method for an optical device according to
claim 23, wherein the connecting member is connected with the
plurality of the metal members through respective connecting parts,
the connecting part is provided with a cutting-off part at least
whose width is narrow or whose thickness is thin, and after the
plurality of the drive magnets and the plurality of the metal
members have been joined to each other, the connecting member is
removed by cutting off the cutting-off part.
25. The manufacturing method for an optical device according to
claim 24, wherein the cutting-off part is formed so that a width of
the cutting-off part is narrow and a thickness of the cutting-off
part is thin, and the cutting-off part is disconnected by bending
repeatedly.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] The present invention claims priority under 35 U.S.C.
.sctn.119 to Japanese Application No. 2010-266749 filed Nov. 30,
2010, the entire content of which is incorporated herein by
reference.
FIELD OF THE INVENTION
[0002] At least an embodiment of the present invention may relate
to an optical device which is provided with a movable body holding
a lens for photography and a fixed body movably holding the movable
body and at least an embodiment of the present invention may relate
to a manufacturing method for the optical device.
BACKGROUND
[0003] Conventionally, as a lens drive device for driving a
photographing lens of a camera which is mounted on a cellular phone
or the like, the present applicant has previously proposed a lens
drive device which is provided with a movable body holding a
plurality of lenses and being moved in an optical axis direction, a
fixed body movably holding the movable body in the optical axis
direction, and a drive mechanism for driving the movable body in
the optical axis direction (see, for example, Japanese Patent
Laid-Open No. 2010-217467). The lens drive device described in the
Patent Literature is formed in a substantially rectangular prism
shape.
[0004] In the lens drive device, the drive mechanism is provided
with four drive magnets formed in a substantially triangular prism
shape and four drive coils which are wound around in a
substantially triangular tube-like shape. The drive magnet is
structured of two drive magnet pieces and a magnetic plate. The two
drive magnet pieces and the magnetic plate are fixed to each other
so that the magnetic plate is sandwiched by the two drive magnet
pieces in an optical axis direction. The two drive magnet pieces
and the magnetic plate are fixed to each other with an adhesive.
The two drive magnet pieces are magnetized so that magnetic poles
of opposing faces of the two drive magnet pieces which face each
other through the magnetic plate are the same magnetic pole.
[0005] Further, the drive magnet is disposed at four corners of the
lens drive device and one end face of the drive magnet in the
optical axis direction is fixed to a cover member structuring the
fixed body with an adhesive. Further, a magnetic piece is fixed to
the other end face of the drive magnet in the optical axis
direction with an adhesive. The drive coil is fixed to the movable
body so that an outer peripheral face of the drive magnet and an
inner peripheral face of the drive coil are faced each other
through a predetermined gap space.
[0006] In recent years, in a market of a camera which is mounted on
a cellular phone or the like, the requirement for reducing the size
of the camera has been further increased and, in order to meet the
requirement, the requirement for reducing the size of a lens drive
device used in the camera has been also increased. In the lens
drive device described in the above-mentioned Patent Literature, in
order to further reduce the size of the device, the drive magnet
and the drive coil are required to be small. On the other hand,
when the drive magnet and the drive coil are small, a drive force
of the drive mechanism for driving the movable body is lowered and
thus a gap space between the drive magnet and the drive coil is
required to be narrow for preventing lowering of the drive force of
the drive mechanism.
[0007] In a case that a gap space between the drive magnet and the
drive coil is set to be narrow, when the gap space is not formed
with a high degree of accuracy, the fixed body to which the drive
magnet is fixed and the movable body to which the drive coil is
fixed may be interfered with each other to cause a problem in
movement of the movable body. However, in the lens drive device
described in the above-mentioned Patent Literature, since two drive
magnet pieces and a magnetic plate are fixed to each other with an
adhesive, in a case that the size of the drive magnet is reduced,
the adhesive may be protruded from a space between the drive magnet
piece and the magnetic plate unless a coating amount and an applied
position of the adhesive are strictly controlled. Therefore, in the
above-mentioned lens drive device, when a gap space between the
drive magnet and the drive coil is set to be narrow with downsizing
of the drive magnet and the drive coil, a problem may occur in
movement of the movable body due to the adhesive which is protruded
from a space between the drive magnet piece and the magnetic
plate.
SUMMARY
[0008] In view of the problem described above, at least an
embodiment of the present invention may advantageously provide an
optical device which is provided with a movable body holding a lens
for photography and a fixed body movably holding the movable body
and is capable of appropriately moving the movable body even when
the size of the device is reduced. Further, at least an embodiment
of the present invention may advantageously provide a manufacturing
method for the optical device.
[0009] According to at least an embodiment of the present
invention, there may be provided an optical device including a
movable body which holds a lens for photography, a fixed body which
movably holds the movable body, a drive magnet and a drive coil for
relatively moving the movable body with respect to the fixed body,
and a metal member which is fixed to the drive magnet. The drive
magnet is fixed to one of the movable body and the fixed body, and
the drive coil is fixed to the other of the movable body and the
fixed body, and the drive magnet and the drive coil are oppositely
disposed to each other through a predetermined gap space. In
addition, a nickel plating layer containing at least nickel is
formed on a surface of the drive magnet and a surface of the metal
member, and the drive magnet and the metal member are joined to
each other by a joining layer which is made of tin-based metal
containing at least tin and is disposed between the drive magnet
and the metal member.
[0010] In accordance with an embodiment of the present invention, a
tin plating layer which covers the nickel plating layer is formed
on the surface of the drive magnet before the metal member is
joined to the drive magnet, and the joining layer is formed by
melting and solidifying the tin plating layer at a time of joining
of the drive magnet to the metal member.
[0011] In the optical device in accordance with the embodiment of
the present invention, the drive magnet and the metal member are
joined to each other through a joining layer which is made of
tin-based metal and is disposed between the drive magnet and the
metal member. Therefore, for example, when a tin plating layer
which is formed to cover a nickel plating layer on the surface of
the drive magnet before joined to the metal member is melted and
solidified at the time when the drive magnet and the metal member
are to be joined to each other, the joining layer is formed and the
drive magnet and the metal member are joined to each other.
Accordingly, in the embodiment of the present invention, the
joining layer is prevented from protruding from a space between the
drive magnet and the metal member which have been joined to each
other. As a result, according to the embodiment of the present
invention, even when a gap space between the drive magnet and the
drive coil is set to be narrow in order to prevent a drive force
from being lowered due to downsizing of the drive magnet and the
drive coil, the gap space between the drive magnet and the drive
coil is formed with a high degree of accuracy and thus an
interference of the movable body with the fixed body is prevented.
In other words, according to the embodiment of the present
invention, even when the size of the optical device is reduced by
reducing the sizes of the drive magnet and the drive coil and by
narrowing a gap space between the drive magnet and the drive coil,
an interference of the movable body with the fixed body is
prevented and the movable body is moved appropriately.
[0012] In accordance with an embodiment of the present invention,
the tin plating layer is melted by induction heating at the time of
joining of the drive magnet to the metal member. In accordance with
an embodiment of the present invention, the tin plating layer may
be melted by abutting a heater chip with the metal member and the
like at the time of joining of the drive magnet to the metal
member. However, in this case, a temperature of the metal member
may become non-uniform according to an abutting condition of the
heater chip with the metal member and thus a joining strength of
the drive magnet to the metal member may be varied. On the other
hand, in a case that the tin plating layer is to be melted by
induction heating, the drive magnet and the metal member are set in
the induction coil and the metal member and the like are heated. As
a result, the tin plating layer is melted and thus the temperature
of the metal member becomes uniform and variation of the joining
strength of the drive magnet to the metal member can be prevented.
Further, in a case that the tin plating layer is melted by abutting
the heater chip with the metal member, a relative position of the
drive magnet and the metal member may be displaced due to abutting
of the heater chip with the metal member when the tin plating layer
is to be melted. On the other hand, in a case that the tin plating
layer is melted by induction heating, the tin plating layer is
melted without abutting of the drive magnet and the metal member
with the induction coil and thus displacement of a relative
position of the drive magnet from the metal member is prevented
when the tin plating layer is to be melted.
[0013] In accordance with an embodiment of the present invention,
the metal member is fixed to an end face of the drive magnet in an
optical axis direction of the lens, and the drive magnet and the
drive coil are oppositely disposed to each other through a
predetermined gap space in a direction perpendicular to the optical
axis direction of the lens.
[0014] In accordance with an embodiment of the present invention,
at least a part of the joining layer and the drive coil are
oppositely disposed to each other through a predetermined gap
space. According to the embodiment of the present invention,
protruding of the joining layer from a space between the drive
magnet and the metal member which have been joined to each other is
prevented and thus, even when at least a part of the joining layer
and the drive coil are oppositely disposed to each other through a
predetermined gap space, an interference of the movable body with
the fixed body is prevented.
[0015] In accordance with an embodiment of the present invention,
the optical device is, as the metal member, provided with a first
metal member and a second metal member which are fixed to the drive
magnet so that the drive magnet is sandwiched. In this case, for
example, in a case that the drive magnet and the metal member are
to be joined to each other, when the first metal member and the
second metal member disposed so that the drive magnet is sandwiched
are heated and the tin plating layers on the surfaces of the drive
magnet are melted and solidified, the drive magnet, the first metal
member and the second metal member are fixed to each other at a
time.
[0016] In accordance with an embodiment of the present invention,
the optical device is provided with one piece of the first metal
member, a plurality of the second metal members, and a plurality of
the drive magnets. Each of the plurality of the second metal
members is fixed to each of the plurality of the drive magnets, and
each of the plurality of the second metal member is formed with a
removing trace which is formed when a connecting member for
connecting the plurality of the second metal members with each
other has been removed. In other words, it is preferable that a
plurality of the second metal members before being joined to a
plurality of the drive magnets is connected with each other through
a connecting member. According to this structure, after a plurality
of the second metal members having been connected with each other
and a plurality of the drive magnets are joined to each other, the
connecting member can be removed. Therefore, when the second metal
members and the drive magnets are to be joined to each other,
displacement of relative position between a plurality of the second
metal members is prevented and thus relative positional accuracy
between a plurality of the second metal members after having been
joined can be enhanced.
[0017] In accordance with an embodiment of the present invention,
the removing trace is formed at a tip end of a protruded part whose
base end part is connected with the second metal member and a width
of the removing trace is narrower than a width of the base end part
of the protruded part and/or a thickness of the removing trace is
thinner than a thickness of the base end part of the protruded
part. According to this structure, after a plurality of the second
metal members having been connected with each other and a plurality
of the drive magnets are joined to each other, the connecting
member is easily removed from a plurality of the second metal
members. Therefore, after a plurality of the second metal members
having been connected with each other and a plurality of the drive
magnets are joined to each other, even when the connecting member
is removed from a plurality of the second metal members, fixed
positions of the second metal members fixed to the drive magnets
are prevented from being displaced.
[0018] In accordance with an embodiment of the present invention,
the movable body is held by the fixed body movably in the optical
axis direction of the lens, the drive coil is fixed to the movable
body, the drive magnet is fixed to the fixed body, and the drive
coil and the drive magnet relatively move the movable body in the
optical axis direction with respect to the fixed body. In other
words, the optical device is, for example, an optical device which
is provided with a structure for adjusting a focus position of an
optical image.
[0019] In accordance with an embodiment of the present invention,
the drive magnet is formed in a substantially columnar shape or a
substantially flat plate shape and is magnetized so that a magnetic
pole of one face and a magnetic pole of the other face in the
optical axis direction are different from each other, the drive
coil is oppositely disposed to a side face of the drive magnet in a
direction perpendicular to the optical axis direction through a
predetermined gap space so as to cover a part of the side face of
the drive magnet, and the metal member is fixed to each of both
sides of the drive magnet in the optical axis direction. In this
case, for example, the metal member which is fixed to one face of
the drive magnet in the optical axis direction is a cover member
structuring an outer peripheral face of the optical device, and the
cover member is formed to cover the metal member which is fixed to
the other face of the drive magnet in the optical axis
direction.
[0020] In accordance with an embodiment of the present invention,
the movable body is movably held by the fixed body so that an
optical axis of the lens is inclined, the drive coil is fixed to
the movable body, the drive magnet is fixed to the fixed body, and
the drive coil and the drive magnet swings the movable body with
respect to the fixed body. In other words, the optical device is,
for example, an optical device which is provided with a structure
for correcting a shake of an optical image.
[0021] In accordance with an embodiment of the present invention,
the drive magnet is formed in a substantially flat plate shape and
is magnetized so that a magnetic pole of one side face and a
magnetic pole of the other side face in a direction perpendicular
to the optical axis direction are different from each other, the
drive coil is oppositely disposed to a side face of the drive
magnet in a direction perpendicular to the optical axis direction
through a predetermined gap space, and the metal member is fixed to
each of both end faces of the drive magnet in the optical axis
direction. Further, in this case, the optical device is provided
with a plurality of drive magnets and a plurality of drive coils
and the plurality of the drive magnets is fixed to an outer
peripheral face of the movable body. The fixed body is provided
with a case body which is formed in a substantially tube-like shape
and structures an outer peripheral face of the optical device, the
plurality of the drive coils is fixed to an inner peripheral face
of the case body so as to respectively face the plurality of the
drive magnets, and the plurality of the drive magnets is connected
by the metal member.
[0022] Further, according to at least an embodiment of the present
invention, there may be provided a manufacturing method for an
optical device provided with a movable body which holds a lens for
photography, a fixed body which movably holds the movable body, a
drive magnet and a drive coil for relatively moving the movable
body with respect to the fixed body, and a metal member which is
fixed to the drive magnet. The drive magnet is fixed to one of the
movable body and the fixed body, and the drive coil is fixed to the
other of the movable body and the fixed body, and the drive magnet
and the drive coil are oppositely disposed to each other through a
predetermined gap space. In the optical device, the manufacturing
method includes forming a nickel plating layer containing at least
nickel on a surface of the drive magnet and a surface of the metal
member, forming a tin plating layer which is made of tin-based
metal containing at least tin on the surface of the drive magnet
before the metal member is joined so as to cover the nickel plating
layer, and melting and solidifying the tin plating layer to join
the drive magnet and the metal member to each other at a time of
joining of the drive magnet to the metal member.
[0023] In accordance with an embodiment of the present invention,
the tin plating layer is melted by heating when the drive magnet
and the metal member are held in a pressurized state. For example,
the tin plating layer is melted by induction heating. In this case,
it may be manufactured that the drive magnet before being joined to
the metal member is in a non-magnetized state, and the drive magnet
is magnetized after the drive magnet and the metal member are
joined to each other.
[0024] According to the manufacturing method for an optical device
in accordance with the embodiment of the present invention, the
drive magnet and the metal member are joined to each other by
melting and solidifying the tin plating layer. Therefore, according
to the embodiment of the present invention, the joining layer is
prevented from protruding from a space between the drive magnet and
the metal member having been joined. In other words, according to
the embodiment of the present invention, even when the size of the
optical device is reduced by reducing the sizes of the drive magnet
and the drive coil and by narrowing a gap space between the drive
magnet and the drive coil, an interference of the movable body with
the fixed body is prevented and the movable body is moved
appropriately.
[0025] In accordance with an embodiment of the present invention,
the drive magnet is comprised of a plurality of the drive magnets,
the metal member is comprised of a plurality of the metal members
which is fixed to each of the plurality of the drive magnets, and
each of the plurality of the metal members is formed so that, after
the plurality of the drive magnets and the plurality of the metal
members are joined to each other in a state that the plurality of
the metal members are connected with each other through a
connecting member, the connecting member is removed. According to
the embodiment of the present invention, after a plurality of the
metal members having been connected with each other and a plurality
of the drive magnets are joined to each other, the connecting
member is removed. Therefore, when the metal members and the drive
magnets are to be joined to each other, displacement of relative
position between a plurality of the metal members is prevented and
thus relative positional accuracy between a plurality of the metal
members after having been joined can be enhanced.
[0026] In accordance with an embodiment of the present invention,
the connecting member is connected with the plurality of the metal
members through respective connecting parts, and the connecting
part is provided with a cutting-off part at least whose width is
narrow or whose thickness is thin and, after the plurality of the
drive magnets and the plurality of the metal members have been
joined to each other, the connecting member is removed by cutting
off the cutting-off part. According to the embodiment of the
present invention, after a plurality of the metal members having
been connected with each other and a plurality of the drive magnets
are joined to each other, the connecting member is easily removed
from a plurality of the metal members. In accordance with an
embodiment of the present invention, when the cutting-off part is
formed so that its width is narrow and its thickness is thin so as
to be capable of being disconnected by bending repeatedly, the
cutting-off part is further easily disconnected.
[0027] Other features and advantages of the invention will be
apparent from the following detailed description, taken in
conjunction with the accompanying drawings that illustrate, by way
of example, various features of embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Embodiments will now be described, by way of example only,
with reference to the accompanying drawings which are meant to be
exemplary, not limiting, and wherein like elements are numbered
alike in several Figures, in which:
[0029] FIG. 1 is a perspective view showing an optical device in
accordance with a first embodiment of the present invention.
[0030] FIG. 2 is a cross-sectional view showing an "E-E" cross
section of the optical device in FIG. 1.
[0031] FIG. 3 is a perspective view showing a state where drive
magnets are fixed to a cover member which is shown in FIG. 1.
[0032] FIG. 4 is a view showing a state where a movable body, a
base member and the like are detached from the optical device shown
in FIG. 1 and which is viewed from an opposite-to-object side.
[0033] FIG. 5 is an exploded perspective view showing a state
before the cover member, the drive magnets and a magnetic member
connecting body shown in FIG. 3 are joined to each other.
[0034] FIG. 6 is a perspective view showing a state after the cover
member, the drive magnets and the magnetic member connecting body
shown in FIG. 5 have been joined to each other.
[0035] FIG. 7 is a perspective view showing a state after the cover
member, the drive magnets and the magnetic member connecting body
shown in FIG. 6 are joined to each other and which is viewed from
an opposite-to-object side.
[0036] FIGS. 8(A) through 8(D) are plan views showing a magnetic
member connecting body in accordance with another embodiment of the
present invention.
[0037] FIG. 9 is a perspective view showing an optical device in
accordance with a second embodiment of the present invention.
[0038] FIG. 10 is a cross-sectional view showing an "H-H" cross
section of the optical device in FIG. 9.
[0039] FIG. 11 is an exploded perspective view showing drive coils,
drive magnets, magnet connecting members and the like shown in FIG.
10.
[0040] FIG. 12 is a perspective view showing a state where the
magnet connecting members are fixed to the drive magnets shown in
FIG. 11.
[0041] FIG. 13 is a side view showing the drive magnets and the
magnet connecting members shown in FIG. 12.
[0042] FIG. 14 is a view showing a case body, the drive coils, the
drive magnets, the magnet connecting member and the like shown in
FIG. 10 which are viewed from an opposite-to-object side.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] Embodiments of the present invention will be described below
with reference to the accompanying drawings.
First Embodiment
[0044] FIG. 1 is a perspective view showing an optical device 1 in
accordance with a first embodiment of the present invention. FIG. 2
is a cross-sectional view showing an "E-E" cross section of the
optical device 1 in FIG. 1. FIG. 3 is a perspective view showing a
state where drive magnets 13 are fixed to a cover member 10 which
is shown in FIG. 1. FIG. 4 is a view showing a state where a
movable body 2, a base member 11 and the like are detached from the
optical device 1 shown in FIG. 1 and which is viewed from an
opposite-to-object side. In the first embodiment, as shown in FIG.
1 and the like, three directions perpendicular to each other are
set to be an "X" direction, a "Y" direction and a "Z" direction and
the "X" direction is set to be a right and left direction, the "Y"
direction is a front and rear direction, and the "Z" direction is
an up-and-down direction. Further, a "Z1" direction side in FIG. 1
is set to be an "upper" side and a "Z2" direction side is a "lower"
side.
[0045] The optical device 1 in this embodiment is a lens drive
device which is provided with a structure for moving a lens for
photography in an optical axis direction to adjust a focus position
for an optical image. The optical device 1 is mounted and used in a
relatively small camera which is used in a cellular phone, a drive
recorder, a monitoring camera system or the like. In the following
description, the optical device 1 in this embodiment is referred to
as a "lens drive device 1".
[0046] A lens drive device 1 is, as shown in FIG. 1, formed in a
substantially rectangular prism shape as a whole. In other words,
the lens drive device 1 is formed in a substantially rectangular
shape when viewed in a direction of an optical axis "L" (optical
axis direction) of a lens for photography. In this embodiment, the
lens drive device 1 is formed in a substantially square shape when
viewed in the optical axis direction. Further, four side faces of
the lens drive device 1 are substantially parallel to the right and
left direction or the front and rear direction.
[0047] In this embodiment, the "Z" direction (up-and-down
direction) is substantially coincided with the optical axis
direction. Further, in the camera on which the lens drive device 1
in this embodiment is mounted, an imaging element not shown is
disposed on its lower side and an object to be photographed on an
upper side is photographed. In other words, in this embodiment, the
upper side ("Z1" direction side) is an object to be photographed
side (object side) and the lower side ("Z2" direction side) is an
opposite-to-object side (imaging element side and image side).
[0048] As shown in FIGS. 1 and 2, the lens drive device 1 is
provided with a movable body 2, which holds a lens for photography
and is movable in the optical axis direction, a fixed body 3 which
movably holds the movable body 2 in the optical axis direction, and
a drive mechanism 4 for driving the movable body 2 in the optical
axis direction. The movable body 2 is movably held by the fixed
body 3 through a plate spring not shown. The plate spring is, for
example, structured of a movable body side fixed part which is
fixed to the movable body 2, a fixed body side fixed part which is
fixed to the fixed body 3, and a spring part which connects the
movable body side fixed part with the fixed body side fixed part.
The plate spring is disposed on an upper end side and a lower end
side of the movable body 2.
[0049] The movable body 2 is provided with a sleeve 8 which holds a
lens holder 7 to which a plurality of lenses are fixed. The fixed
body 3 is provided with a cover member 10 which structures four
side faces (outer peripheral face) of the lens drive device 1 and a
base member 11 which structures an end face on an
opposite-to-object side of the lens drive device 1.
[0050] The lens holder 7 is formed in a substantially cylindrical
tube shape and a plurality of lenses are fixed to an inner
peripheral side of the lens holder 7. The sleeve 8 is formed in a
substantially tube-like shape and an outer peripheral face of the
lens holder 7 is fixed to an inner peripheral face of the sleeve 8.
Further, a flange part 8a is formed on a lower end side of the
sleeve 8.
[0051] The cover member 10 is formed of magnetic material. The
cover member 10 in this embodiment is formed of a thin steel plate
having a magnetic property. a A nickel plating layer consisting of
nickel or nickel alloy consisting mainly of nickel is formed on a
surface of the cover member 10. The cover member 10 is formed in a
substantially bottomed rectangular tube shape which is provided
with a bottom part 10a and a tube part 10b. The bottom part 10a is
disposed on an upper side and structures an end face on an object
side of the lens drive device 1. A circular through hole 10c is
formed at the center of the bottom part 10a. The cover member 10 is
disposed so as to surround outer peripheral sides of the drive
mechanism 4 and the movable body 2. The base member 11 is formed in
a substantially square frame shape and is attached to a lower end
side of the cover member 10.
[0052] The drive mechanism 4 is provided with four drive magnets
13, which are disposed at four corners of the lens drive device 1
(specifically, four corners on an inner side of the cover member
10) and are formed in a substantially triangular prism shape, and
one drive coil 14 which is fixed to the sleeve 8.
[0053] The drive magnet 13 is a neodymium magnet containing
neodymium, iron and boron as main components. The drive magnet 13
is formed so that its shape when viewed in the upper and lower
direction is a substantially rectangular equilateral triangle. The
drive magnet 13 is provided with two first rectangular side faces
(first side faces) 13a which are substantially parallel to the
optical axis "L" and are perpendicular to each other, and one
second rectangular side face (second side face) 13b which is
substantially parallel to the optical axis "L" for connecting two
first side faces 13a with each other. A nickel plating layer for
rust prevention consisting of nickel or nickel alloy consisting
mainly of nickel is formed on the surface of the drive magnet
13.
[0054] The drive magnet 13 is disposed so that an inner peripheral
face of the tube part 10b of the cover member 10 and the first side
face 13a are substantially parallel to each other and are
oppositely disposed to each other with a predetermined gap space
therebetween. In other words, two drive magnets 13 which are
disposed at diagonal positions on an inner side of the cover member
10 are disposed so that the second side faces 13b are oppositely
disposed to each other. Further, the four drive magnets 13 are
fixed to the bottom part 10a of the cover member 10. Specifically,
upper end faces of the four drive magnets 13 are fixed to the under
face of the bottom part 10a in an abutted state with the under face
of the bottom part 10a. Further, the upper end faces of the four
drive magnets 13 are completely covered by the bottom part 10a.
[0055] In this embodiment, the drive magnet 13 is joined to the
bottom part 10a by a joining layer 15 consisting of tin-based metal
containing at least tin. In other words, as shown in FIG. 2, the
drive magnet 13 and the bottom part 10a are joined to each other by
the joining layer 15 which is disposed between the under face of
the bottom part 10a and the upper face of the drive magnet 13. The
joining layer 15 is structured of tin, tin alloy containing copper,
tin alloy containing gold, tin alloy containing silver, tin alloy
containing bismuth or the like.
[0056] A lower end face of the drive magnet 13 is fixed with a flat
plate-shaped magnetic member 17 which is formed of magnetic
material. The magnetic member 17 in this embodiment is formed of a
stainless steel sheet having a magnetic property. A surface of the
magnetic member 17 is formed with a nickel plating layer which is
consisting of nickel or nickel alloy consisting mainly of nickel
and is easily metallic bonded with the tin metal plating.
[0057] The magnetic member 17 is formed so that, similarly to the
drive magnet 13, its shape when viewed in the upper and lower
direction is a substantially rectangular equilateral triangle. The
magnetic member 17 is provided with two first end faces 17a which
are perpendicular to each other and one second end face 17b which
connects the two first end faces 17a with each other. The magnetic
member 17 is fixed to a lower end face of the drive magnet 13 so
that its thickness direction is substantially coincided with the
upper and lower direction. Further, the magnetic member 17 is fixed
to the lower end face of the drive magnet 13 so that the first end
face 17a is disposed so as to form the same flat face with the
first side face 13a of the drive magnet 13 and the second end face
17b is disposed so as to form the same flat face with the second
side face 13b of the drive magnet 13.
[0058] In this embodiment, the magnetic member 17 is joined to the
drive magnet 13 by a joining layer 18 consisting of tin-based metal
containing at least tin. In other words, as shown in FIG. 2, the
drive magnet 13 and the magnetic member 17 are joined to each other
by the joining layer 18 which is disposed between an under face of
the drive magnet 13 and an upper face of the magnetic member 17.
The joining layer 18 is structured of tin-based metal which is
similar to the tin-based metal structuring the joining layer 15.
The joining layer 18 is structured of tin, tin alloy containing
copper, tin alloy containing gold, tin alloy containing silver, tin
alloy containing bismuth or the like.
[0059] The drive magnet 13 is magnetized in two poles in the upper
and lower direction so that a magnetic pole of its upper end face
and a magnetic pole of its lower end face are different from each
other. For example, the upper end face of the drive magnet 13 is
magnetized in an "S"-pole and the lower end face of the drive
magnet 13 is magnetized in an "N"-pole. Further, the first side
faces 13a of the drive magnet 13 and the first end faces 17a of the
magnetic member 17 are covered by the tube part 10b of the cover
member 10 from outer peripheral sides.
[0060] Therefore, as shown in FIG. 2, in the lens drive device 1, a
magnetic field "F" is formed so as to pass through the tube part
10b and the bottom part 10a of the cover member 10, the drive
magnet 13 and the magnetic member 17 and reach to the inner
peripheral face of the tube part 10b from the under face and the
first end faces 17a of the magnetic member 17. The magnetic field
"F" is formed so as to pass from the under face and the first end
face 17a of the magnetic member 17 toward a portion of the inner
peripheral face of the tube part 10b which is oppositely disposed
in substantially parallel to the first side face 13a of the drive
magnet 13 and the first end face 17a of the magnetic member 17. In
this embodiment, in FIG. 2, although not shown, the magnetic field
"F" is also formed so as to reach to the inner peripheral face of
the tube part 10b from a vicinity of an abutting portion of the
lower end face of the drive magnet 13 with the upper face of the
magnetic member 17.
[0061] The drive coil 14 is wound around in a substantially flat
rectangular tube shape whose shape viewed in the upper and lower
direction is a substantially square shape. A width of the drive
coil 14 in the upper and lower direction is thicker than a
thickness of the magnetic member 17. The drive coil 14 is fixed to
an upper face of the flange part 8a of the sleeve 8 with an
adhesion.
[0062] The drive coil 14 is, as shown in FIG. 4, disposed along the
inner peripheral face of the tube part 10b of the cover member 10.
Four corners and their vicinity portions of the drive coil 14 are
disposed in spaces between the first side faces 13a of the drive
magnets 13, the first end faces 17a of the magnetic members 17 and
the tube part 10b of the cover member 10. In other words, the inner
peripheral faces of the four corners and their vicinity portions of
the drive coil 14 are oppositely disposed to the first side faces
13a of the drive magnets 13 and the first end faces 17a of the
magnetic members 17 with a predetermined gap space therebetween in
the front and rear direction or in the right and left direction. In
other words, a part of the drive coil 14 is oppositely disposed to
parts of the drive magnet 13 and the magnetic member 17 with a
predetermined gap space therebetween so as to cover the parts of
the drive magnet 13 and the magnetic member 17 from an outer
peripheral side. Further, the inner peripheral face of the four
corners and their vicinity portions of the drive coil 14 are also
oppositely disposed to the joining layers 18 which are disposed
between the under face of the drive magnet 13 and the upper face of
the magnetic member 17 with the predetermined gap space
therebetween in the front and rear direction or in the right and
left direction (see FIG. 2). Further, the four corners and their
vicinity portions of the drive coil 14 are disposed in the inside
of the magnetic field "F" which is formed so as to reach to the
inner peripheral face of the tube part 10b from the under face and
the first end face 17a of the magnetic member 17.
[0063] In this embodiment, the drive coil 14 is disposed so that
the magnetic member 17 is always disposed on the inner peripheral
side of the drive coil 14 in a moving range of the movable body 2.
In other words, in the moving range of the movable body 2, the
drive coil 14 is disposed so that the lower end face of the drive
coil 14 is not moved to an upper side with respect to the under
face of the magnetic member 17 and the upper end face of the drive
coil 14 is not moved to a lower side with respect to the upper face
of the magnetic member 17. When an electric current is supplied to
the drive coil 14, the movable body 2 is moved in the upper and
lower direction (optical axis direction) through an operation
between the drive magnets 13 and the drive coil 14. In other words,
the drive magnet 13 and the drive coil 14 relatively move the
movable body 2 in the optical axis direction with respect to the
fixed body 3.
[0064] In this embodiment, the cover member 10 and the magnetic
member 17 are a metal member which is fixed to the drive magnet 13.
Further, the cover member 10 in this embodiment is a first metal
member and the magnetic member 17 is a second metal member.
[0065] FIG. 5 is an exploded perspective view showing a state
before the cover member 10, the drive magnets 13 and a magnetic
member original body 21 shown in FIG. 3 are joined to each other.
FIG. 6 is a perspective view showing a state after the cover member
10, the drive magnets 13 and the magnetic member original body 21
shown in FIG. 5 have been joined to each other. FIG. 7 is a
perspective view showing a state after the cover member 10, the
drive magnets 13 and the magnetic member original body 21 shown in
FIG. 6 have been joined to each other and which is viewed from an
opposite-to-object side.
[0066] Next, a joining method of the cover member 10, the drive
magnets 13 and the magnetic members 17 will be described below.
[0067] A surface of the drive magnet 13 before joined to the cover
member 10 and the magnetic member 17 is formed with tin plating
layers, which become the joining layers 15 and 18 after having been
joined, so as to cover the nickel plating layer. Further, the drive
magnet 13 is not magnetized before joined to the cover member 10
and the magnetic member 17. In this embodiment, a tin plating layer
is not formed so as to cover the nickel plating layer on the
surface of the cover member 10 and the surface of the magnetic
member 17 before joined to the drive magnet 13. However, a tin
plating layer may be formed so as to cover the nickel plating layer
on the cover member 10 and the magnetic member 17. In this case,
when a tin plating layer is melted, the tin plating layer is
discolored by induction heating described below. Therefore, it is
preferable that a tin plating layer is not formed on the cover
member 10 which structures the outer peripheral face of the lens
drive device 1.
[0068] Further, the magnetic members 17 before joined to the drive
magnets 13 are connected through a connecting member 20 for
integrating four magnetic members 17 with each other. The four
magnetic members 17 which are connected with each other through the
connecting member 20 structure the magnetic member connecting body
21. The connecting member 20 is provided with a base part 20a which
is formed in a roughly square frame shape and four substantially
rectangular-shaped connecting parts 20b which are protruded to
outer sides from substantially centers of respective four sides of
the base part 20a. The base part 20a and the four magnetic members
17 are connected with each other through the connecting parts 20b.
Both sides in a widthwise direction of the connecting part 20b at a
boundary portion between the connecting part 20b and the magnetic
member 17 are, as shown in FIG. 7, formed with a substantially
semicircular arc-shaped cutout part 17c which is recessed from the
second end face 17b toward the magnetic member 17. Further, a
grasping part 20c is formed at two positions on a diagonal line of
four corners of the base part 20a for handling the magnetic member
connecting body 21 when the cover member 10, the drive magnets 13
and the magnetic members 17 are to be joined to each other or the
like.
[0069] When the cover member 10, the drive magnets 13 and the
magnetic members 17 are to be joined to each other, first, a
magnetic member connecting body 21 is set into a recessed portion
which is formed in a joining jig and the magnetic member connecting
body 21 is positioned.
[0070] After that, the drive magnets 13 are set on the magnetic
members 17 so that each of the four drive magnets 13 are pressed
against each of four guide members 22 (see FIG. 4) which is formed
in the joining jig. The guide member 22 is, as shown in FIG. 4,
formed in a substantially "L"-shape. When the first side faces 13a
of the drive magnet 13 are pressed against inner side faces of the
guide member 22, the drive magnet 13 is set on the magnetic member
17 so that the first side faces 13a and the first end faces 17a of
the magnetic member 17 are disposed so as to form the same flat
face as each other and so that the second side face 13b of the
drive magnet 13 and the second end face 17b of the magnetic member
17 are disposed so as to form the same flat face as each other.
After that, a nesting 23 in a substantially cylindrical shape (see
FIG. 4) which is formed so as to be abutted with the second side
faces 13b of the four drive magnets 13 is set and the drive magnets
13 are positioned.
[0071] After that, the cover member 10 is placed so as to cover the
drive magnets 13 and the magnetic member connecting body 21 so that
the under face of the bottom part 10a of the cover member 10 and
the upper end faces of the drive magnets 13 are abutted with each
other and, in this manner, the cover member 10 is set. In this
case, the inner peripheral face of the tube part 10b of the cover
member 10 is guided by the outer side faces of the guide members 22
and the cover member 10 is positioned.
[0072] After that, the cover member 10, the drive magnets 13 and
the magnetic member connecting body 21 are disposed in an induction
coil. Further, an electric current is supplied to the induction
coil while pressurizing and holding so that the cover member 10 and
the drive magnets 13 are tightly contacted with each other and the
drive magnets 13 and the magnetic member connecting body 21 are
tightly contacted with each other. When an electric current is
supplied to the induction coil, the cover member 10, the drive
magnets 13 and the magnetic member connecting body 21 are heated by
operations of eddy currents generated in the cover member 10, the
drive magnets 13 and the magnetic member connecting body 21, the
tin plating layers on the surfaces of the drive magnets 13 are
melted. In other words, the tin plating layers on the surfaces of
the drive magnets 13 are melted by induction heating. Further, when
the supply of the electric current to the induction coil is
stopped, the melted tin-based metal is solidified to form joining
layers 15 and 18 and the cover member 10, the drive magnets 13 and
the magnetic member connecting body 21 are joined to each other by
the joining layers 15 and 18. In this embodiment, at the time of
induction heating, the cover member 10, the drive magnets 13 and
the magnetic member connecting body 21 are heated to about
230.degree. C.(degree C.)-300.degree. C.(degree C.).
[0073] After that, the connecting member 20 of the magnetic member
connecting body 21 is removed. Specifically, boundary portions
between the connecting parts 20b and the magnetic members 17 are
cut off and the connecting member 20 is removed. The boundary
portion between the connecting part 20b and the magnetic member 17
is, for example, disconnected by a mechanical cutting, a laser
cutting or the like. When the connecting member 20 is removed, the
magnetic member 17 is, as shown in FIG. 4, formed with a removing
trace 17d. In this case, substantially semicircular arc-shaped
cutout parts 17c which are recessed to the magnetic member 17 side
from the second end face 17b are formed on both sides in a
widthwise direction of the connecting part 20b at a boundary
portion between the connecting part 20b and the magnetic member 17.
Therefore, when the boundary portion between the connecting part
20b and the magnetic member 17 is cut and disconnected, a portion
of the removing trace 17d can be formed so as not to protrude to an
inner side (movable body 2 side) with respect to the second end
face 17b. The removing trace 17d is formed at a tip end of a
protruded part 17e whose base end part is connected with the
magnetic member 17. In this embodiment, after the cover member 10,
the drive magnets 13 and the magnetic members 17 are joined to each
other, the four drive magnets 13 are simultaneously magnetized.
[0074] As described above, in this embodiment, the drive magnet 13
and the magnetic member 17 are joined to each other by the joining
layer 18 which is formed so that the tin plating layers on the
surfaces of the drive magnet 13 before joined to the cover member
10 and the magnetic member 17 are melted and solidified. Therefore,
the joining layer 18 is not protruded from a portion between the
drive magnet 13 and the magnetic member 17. Accordingly, in this
embodiment, even when a gap space between the drive magnet 13 and
the drive coil 14 is set to be narrow in order to prevent a drive
force from being lowered due to downsizing of the drive magnet 13
and the drive coil 14, the gap space between the drive magnet 13,
the magnetic member 17 and the joining layer 18 and the drive coil
14 is formed with a high degree of accuracy. As a result, an
interference of the movable body 2 with the fixed body 3 is
prevented. In other words, in this embodiment, even when the size
of the lens drive device 1 is reduced by reducing the sizes of the
drive magnet 13 and the drive coil 14 and by narrowing a gap space
between the drive magnet 13 and the drive coil 14, an interference
of the movable body 2 with the fixed body 3 is prevented and the
movable body 2 is moved appropriately.
[0075] Further, in this embodiment, the joining layer 18 is not
protruded from a portion between the drive magnet 13 and the
magnetic member 17 and thus a gap space between the drive magnet
13, the magnetic member 17 and the joining layer 18 and the outer
peripheral face of the sleeve 8 is formed with a high degree of
accuracy. Therefore, an interference of the movable body 2 with the
fixed body 3 is also prevented on the inner peripheral side of the
drive magnet 13.
[0076] In this embodiment, the tin plating layers which are formed
on the surfaces of the drive magnet 13 before joined to the cover
member 10 and the magnetic member 17 are melted by induction
heating. In other words, in this embodiment, the cover member 10,
the drive magnets 13 and the magnetic member connecting body 21 are
disposed in the induction coil and an electric current is supplied
to the induction coil to melt the tin plating layer. Therefore,
temperatures of the cover member 10, the drive magnets 13 and the
magnetic member connecting body 21 when the tin plating layers are
to be melted are made uniform and thus variation of joining
strengths of the cover member 10 to the drive magnets 13 and
variation of joining strengths of the drive magnets 13 to the
magnetic member connecting body 21 can be prevented. Further, in
this embodiment, the tin plating layer can be melted without
contacting the cover member 10, the drive magnets 13 and the
magnetic member connecting body 21 with the induction coil.
Therefore, relative positional displacement of the cover member 10,
the drive magnets 13 and the magnetic member connecting body 21
from each other is prevented when the tin plating layers are to be
melted.
[0077] In this embodiment, in a state that the drive magnet 13 is
sandwiched between the bottom part 10a of the cover member 10 and
the magnetic member connecting body 21, the tin plating layers on
the surfaces of the drive magnet 13 are melted and solidified to
form the joining layers 15 and 18. Therefore, the cover member 10,
the drive magnets 13 and the magnetic member connecting body 21 are
fixed to each other by one operation. Accordingly, in this
embodiment, a fixing operation of the cover member 10, the drive
magnets 13 and the magnetic member connecting body 21 to each other
is easily performed.
[0078] In this embodiment, the four magnetic members 17 before
joined to the drive magnets 13 are connected and integrated with
each other by the connecting member 20. Therefore, a relative
positional accuracy of the four magnetic members 17 to each other
when joined to the drive magnets 13 is enhanced and, as a result,
in the lens drive device 1 after having been assembled, a relative
positional accuracy of the four magnetic members 17 is
enhanced.
[0079] In this embodiment, the cover member 10, the drive magnet 13
and the magnetic member 17 are joined to each other by the joining
layers 15 and 18 consisting of tin-based metal. Therefore, in
comparison with a case that the cover member 10, the drive magnet
13 and the magnetic member 17 are joined to each other with an
adhesive, loss of magnetic flux passing through the cover member
10, the drive magnet 13 and the magnetic member 17 is reduced.
Accordingly, in this embodiment, a magnetic circuit having a
satisfactory efficiency can be formed. Further, in comparison with
a case that the cover member 10, the drive magnet 13 and the
magnetic member 17 are joined to each other with an adhesive, in
this embodiment, a time for joining can be shortened.
[0080] FIGS. 8(A) through 8(D) are plan views showing magnetic
member connecting bodies 31, 33, 35 and 37 in accordance with
another embodiment of the present invention.
[0081] In the embodiment described above, four magnetic members 17
are integrated with each other by the connecting member 20 which is
provided with the base part 20a formed in a roughly square frame
shape and four substantially rectangular-shaped connecting parts
20b which are protruded to outer sides from respective
substantially center portions of four sides of the base part 20a
and, in this manner, the magnetic member connecting body 21 is
structured. However, the present invention is not limited to this
embodiment. For example, as shown in FIG. 8(A), four magnetic
members 17 may be integrated with each other by a connecting member
30 which is provided with two first base parts 30a formed in a
substantially "V"-shape, two second base parts 30b which connect
the two first base parts 30a with each other, and connecting parts
30c which are protruded to outer sides from the first base parts
30a and, in this manner, the magnetic member connecting body 31 is
structured. Further, as shown in FIG. 8(B), four magnetic members
17 may be integrated with each other by a connecting member 32
which is provided with two first base parts 32a formed in a
substantially "V"-shape, two second base parts 32b which connect
the two first base parts 32a with each other, and connecting parts
32c which are protruded to outer sides from the first base parts
32a and, in this manner, the magnetic member connecting body 33 is
structured.
[0082] In the connecting members 30 or 32, two connecting parts 30c
or 32c are formed in the one first base part 30a or 32a and one
first base part 30a or 32a and two magnetic members 17 are
connected with each other by the connecting parts 30c or 32c. A
boundary part 30d which is used as a cutting-off part is formed
between the connecting part 30c and the magnetic member 17, and a
boundary part 30e which is used as a cutting-off part is formed
between the first base part 30a and the second base part 30b. A
boundary part 32d is formed between the connecting part 32c and the
magnetic member 17 and a boundary part 32e is formed between the
first base part 32a and the second base part 32b. The boundary
parts 30d, 30e, 32d and 32e are formed so that their widths become
narrow and their thicknesses become thin toward their centers.
[0083] In the cases of the magnetic member connecting bodies 31 and
33, after the cover member 10, the drive magnets 13 and the
magnetic member connecting body 31 or 33 have been joined to each
other, the boundary parts 30d, 30e, 32d and 32e are, for example,
bent repeatedly for disconnection and the connecting members 30 and
32 are removed. Specifically, first, the boundary parts 30e and 32e
are cut off to remove the second base parts 30b and 32b and, after
that, the boundary parts 30d and 32d are cut off to remove the
first base parts 30a and 32a. In these cases, the boundary parts
30d, 30e, 32d and 32e are disconnected at center positions of the
boundary parts 30d, 30e, 32d and 32e where the width is narrow and
the thickness is thin.
[0084] The magnetic members 17 after the connecting members 30 and
32 have been removed are formed with protruded parts 17g which
structure parts of the boundary parts 30d and 32d. In this case,
since the protruded part 17g is formed in a recessed part which is
formed in a side face of the magnetic member 17, the protruded part
17g does not protrude to the movable body 2 side from the side face
of the magnetic member 17. A tip end of the protruded part 17g is a
removing trace 17h which is formed when the connecting members 30
and 32 are removed. A width of the removing trace 17h is narrower
than a width of the base end of the protruded part 17g and a
thickness of the removing trace 17h is thinner than a thickness of
the base end of the protruded part 17g. However, according to
conditions when the connecting members 30 and 32 are removed, a
thickness of the removing trace 17h may be thicker than a thickness
of the base end of the protruded part 17g.
[0085] Further, as shown in FIG. 8(C), four magnetic members 17 may
be integrated with each other by a connecting member 34 which is
provided with two first base parts 34a formed in a roughly
"V"-shape and one second base part 34b which connects the two first
base parts 34a with each other and, in this manner, a magnetic
member connecting body 35 is structured. Further, as shown in FIG.
8(D), four magnetic members 17 may be integrated with each other by
a connecting member 36 which is provided with two first base parts
36a formed in a roughly "V"-shape and one second base part 36b
which connects the two first base parts 36a with each other and, in
this manner, a magnetic member connecting body 37 is
structured.
[0086] In the connecting member 34 or 36, two magnetic members 17
are connected with one first base part 34a or 36a. A boundary part
34d is formed between the first base part 34a and the magnetic
member 17 and a boundary part 34e is formed between the first base
part 34a and the second base part 34b. A boundary part 36d is
formed between the first base part 36a and the magnetic member 17
and a boundary part 36e is formed between the first base part 36a
and the second base part 36b. Further, the second base part 36b is
formed with bending parts 36f for bending the second base part 36b.
The boundary parts 34d, 34e and 36d are formed so that their widths
become narrow and their thicknesses become thin toward their
centers. The boundary part 36e and the bending part 36f are formed
so that their thicknesses become thin toward their centers.
[0087] In a case of the magnetic member connecting body 35, after
the cover member 10, the drive magnets 13 and the magnetic member
connecting body 35 have been joined to each other, the boundary
parts 34d are, for example, bent repeatedly for disconnection and
the connecting member 34 is removed. Specifically, first, the
boundary parts 34e are bent and, while grasping the second base
part 34b, the boundary parts 34d are bent repeatedly for
disconnection to remove the connecting member 34. In this case, the
boundary part 34d is cut off at a center position of the boundary
part 34d where the width is narrow and the thickness is thin.
[0088] Further, in a case of the magnetic member connecting body
37, after the cover member 10, the drive magnets 13 and the
magnetic member connecting body 37 have been joined with each
other, the boundary parts 36d are, for example, bent repeatedly for
disconnection and the connecting member 36 is removed.
Specifically, first, the bending parts 36f are bent and, while
grasping the second base part 36b, the boundary parts 36d are bent
repeatedly for disconnection to remove the connecting member 36. In
this case, the boundary part 36d is disconnected at a center
position of the boundary part 36d where the width is narrow and the
thickness is thin.
[0089] The magnetic members 17 after the connecting members 34 and
36 have been removed are, similarly to the magnetic members 17
after the connecting members 30 and 32 have been removed, formed
with protruded parts 17g which structure parts of the boundary
parts 34d and 36d. A tip end of the protruded part 17g is a
removing trace 17h which is formed when the connecting members 34
and 36 have been removed. A width of the removing trace 17h is
narrower than a width of a base end of the protruded part 17g and a
thickness of the removing trace 17h is thinner than a thickness of
the base end of the protruded part 17g. However, according to
conditions when the connecting members 30 and 32 are removed, a
thickness of the removing trace 17h may be thicker than a thickness
of the base end of the protruded part 17g.
[0090] In the magnetic member connecting bodies 31, 33, 35 and 37,
the boundary parts 30d, 32d, 34d and 36d are formed so that their
widths become narrow and their thicknesses become thin toward their
centers. Therefore, the connecting members 30, 32, 34 and 36 are
easily removed from the magnetic member connecting bodies 31, 33,
35 and 37. Accordingly, when the connecting members 30, 32, 34 and
36 are to be removed from the magnetic member connecting bodies 31,
33, 35 and 37, the fixed positions of the magnetic members 17 which
are fixed to the drive magnets 13 are prevented from being
displaced. In accordance with an embodiment of the present
invention, even when the boundary parts 30d, 32d, 34d and 36d are
formed so that their thicknesses are constant and their widths
become narrow toward their centers or, even when the boundary parts
30d, 32d, 34d and 36d are formed so that their widths are constant
and their thicknesses become thin toward their centers, this effect
can be obtained.
[0091] In the first embodiment, the magnetic members 17 before
joined to the drive magnets 13 are connected by the connecting
member 20. However, the magnetic members 17 before joined to the
drive magnets 13 may not be connected by the connecting member 20.
In other words, when the cover member 10, the drive magnets 13 and
the magnetic members 17 are to be joined to each other, four
separated magnetic members 17 may be set in a joining jig.
[0092] In the first embodiment, the drive mechanism 4 is provided
with one drive coil 14 which is disposed along the inner peripheral
face of the tube part 10b of the cover member 10. However, the
drive mechanism 4 may be provided, instead of the drive coil 14,
with four drive coils each of which is wound in a substantially
triangular tube-like shape and whose inner peripheral side is
oppositely disposed to a side face of the drive magnet 13 with a
predetermined gap space. In this case, the drive coil is wound
around so that a shape when viewed in the upper and lower direction
is a substantially rectangular equilateral triangular shape and the
drive coil is fixed to the sleeve 8 so that the inner peripheral
face of the drive coil and the side face of the drive magnet 13 are
substantially parallel to each other with a predetermined gap space
therebetween.
[0093] In the first embodiment, the drive magnet 13 is formed in a
substantially triangular prism shape. However, the drive magnet 13
may be formed in a substantially polygonal pillar shape other than
a substantially triangular prism shape, a substantially cylindrical
pillar shape or a substantially elliptic pillar shape. Further, in
the first embodiment, the lens drive device 1 is formed so that a
shape when viewed in the optical axis direction is a substantially
quadrangular shape. However, the lens drive device 1 may be formed
so that a shape when viewed in the optical axis direction is a
roughly polygonal shape other than a substantially rectangular
shape or a shape when viewed in the optical axis direction is a
roughly circular shape or a roughly elliptic shape.
[0094] In the first embodiment, the shape of the drive magnet 13
and the shape of the magnetic member 17 when viewed in the upper
and lower direction are substantially same as each other. However,
the shape of the drive magnet 13 and the shape of the magnetic
member 17 when viewed in the upper and lower direction may be
different from each other. Further, in the first embodiment, the
drive magnet 13 is disposed at four corners of the lens drive
device 1. However, when a sufficient drive force for the movable
body 2 is obtained, the drive magnet 13 may be disposed at three
positions, two positions or only one position of four corners of
the lens drive device 1.
Second Embodiment
[0095] FIG. 9 is a perspective view showing an optical device 51 in
accordance with a second embodiment of the present invention. FIG.
10 is a cross-sectional view showing an "H-H" cross section of the
optical device 51 in FIG. 9. FIG. 11 is an exploded perspective
view showing drive coils 67, drive magnets 68, magnet connecting
members 74 and 75 and the like shown in FIG. 10. FIG. 12 is a
perspective view showing a state where the magnet connecting
members 74 and 75 are fixed to the drive magnets 68 shown in FIG.
11. FIG. 13 is a side view showing the drive magnets 68 and the
magnet connecting members 74 and 75 shown in FIG. 12. FIG. 14 is a
view showing a case body 62, the drive coils 67, the drive magnets
68, the magnet connecting member 74 and the like shown in FIG. 10
which are viewed from an opposite-to-object side. In the second
embodiment, as shown in FIG. 9, three directions perpendicular to
each other are set to be an "X" direction, a "Y" direction and a
"Z" direction and the "X" direction is set to be a right and left
direction, the "Y" direction is a front and rear direction, and the
"Z" direction is an upper-and-lower direction. Further, a "Z1"
direction side is set to be an "upper" side and a "Z2" direction
side is a "lower" side.
[0096] The optical device 51 in this embodiment is a small and thin
camera which is mounted on a portable apparatus such as a cellular
phone, a drive recorder, a monitoring camera system or the like and
which is provided with an autofocus function and a shake correcting
function. The optical device 51 is formed in a substantially
rectangular prism-like shape as a whole. In this embodiment, the
optical device 51 is formed so that a shape when viewed in a
direction of an optical axis "L" of a lens for photography (optical
axis direction) is a substantially square shape and four side faces
of the optical device 51 are substantially parallel to the right
and left direction or the front and rear direction.
[0097] The optical device 51 is, as shown in FIGS. 9 and 10,
provided with a camera module 52 as a movable body which holds a
lens and an imaging element, a fixed body 53 which swingably holds
the camera module 52 so that the optical axis "L" is inclined, a
plate spring 54 which connects the camera module 52 with the fixed
body 53, and a swing drive mechanism 55 which swings the camera
module 52 with respect to the fixed body 53 for correcting a shake
of an optical image that is imaged on an imaging element. In this
embodiment, the upper and lower direction is substantially
coincided with an optical axis direction of the camera module 52
when the camera module 52 is not swung. Further, in this
embodiment, an imaging element is mounted on a lower end of the
camera module 52 for photographing an object to be photographed
which is disposed on an upper side. In other words, in this
embodiment, an upper side ("Z1" direction side) is an object to be
photographed side (object side) and a lower side ("Z2" direction
side) is an opposite-to-object side (imaging element side and image
side).
[0098] The camera module 52 is formed in a substantially
rectangular prism-like shape as a whole. In this embodiment, the
camera module 52 is formed so that a shape when viewed in the
optical axis direction is a substantially square shape. The camera
module 52 is provided with a movable body, which holds a lens and
is movable in the optical axis direction, a holding body which
movably holds the movable body in the optical axis direction, and a
drive mechanism for driving the movable body in the optical axis
direction with respect to the holding body. The lens drive
mechanism is, for example, structured of drive coils and drive
magnets. In accordance with an embodiment of the present invention,
the lens drive mechanism may be structured of a piezoelectric
element, a shape-memory alloy or the like.
[0099] A board 57 is fixed to an under face of the camera module
52. An imaging element is mounted on the board 57. Further, the
board 57 is mounted with a gyroscope for detecting a variation of
an inclination of the camera module 52. An FPC (flexible printed
circuit board) 58 is connected with the board 57. The FPC 58 is
extended along a lower end side of the optical device 51 and is
drawn out from a side face of the optical device 51. Further, an
under face of the board 57 is, as shown in FIG. 10, fixed with an
abutting plate 59 which is abutted with a spherical member 64
described below.
[0100] The fixed body 53 is provided with a case body 62, which
structures four front, rear, right and left side faces (outer
peripheral face) of the optical device 51, and a lower case body 63
which structures an under face side of the optical device 51. The
case body 62 is formed in a substantially rectangular tube shape
and is disposed so as to surround the camera module 52 from an
outer peripheral side. The lower case body 63 is formed in a
substantially rectangular tube shape with a bottom (substantially
bottomed rectangular tube shape) which is provided with a bottom
part 63a and a tube part 63b.
[0101] The bottom part 63a of the lower case body 63 is disposed on
a lower side and structures an under face of the optical device 51.
Further, a center of the bottom part 63a is formed with an
arrangement hole 63c to which a lower end side of the spherical
member 64 serving as a supporting point for swinging of the camera
module 52 is disposed. In this embodiment, a supporting point part
65 which is a swing center of the camera module 52 is structured of
the spherical member 64 and the arrangement hole 63c. The
supporting point part 65 is disposed on a lower side of the camera
module 52 and an upper end of the spherical member 64 is abutted
with an under face of the abutting plate 59.
[0102] The swing drive mechanism 55 is provided with four drive
coils 67 and four drive magnets 68 each of which is oppositely
disposed to each of the four drive coils 67.
[0103] The four drive coils 67 are, as shown in FIG. 11, pattern
coils which are formed in the FPC 69 in itself. Further, the drive
coil 67 is formed to be wound around in a roughly rectangular shape
and is provided with two long side parts 67a which are
substantially parallel to each other. The FPC 69 is disposed along
an inner peripheral face of the case body 62 so that each of the
four drive coils 67 is disposed on each of four inner side faces
which structures the inner peripheral face of the case body 62.
Further, the FPC 69 is fixed to the inner peripheral face of the
case body 62 so that the long side parts 67a are substantially
parallel to the front and rear direction or the right and left
direction. The FPC 69 is connected with the FPC 58 through a
relaying FPC 70. In accordance with an embodiment of the present
invention, the drive coil 67 may be an air-core coil which is wound
around in an air-core shape. In this case, the drive coil 67 may be
fixed to each of the inner side faces of the case body 62 or four
drive coils 67 may be mounted on the FPC 69.
[0104] The drive magnet 68 is a neodymium magnet containing
neodymium, iron and boron as main components. The drive magnet 68
is formed in a substantially rectangular flat plate shape. Further,
the drive magnet 68 is structured of two magnet pieces which are a
magnet piece 72 and a magnet piece 73 formed in a substantially
rectangular flat plate shape. Specifically, the magnet piece 72 and
the magnet piece 73 are adhesively fixed to each other in a state
that an under face of the magnet piece 72 and an upper face of the
magnet piece 73 are abutted with each other to form the drive
magnet 68. A nickel plating layer consisting of nickel or nickel
alloy consisting mainly of nickel is formed on the surface of the
drive magnet 13.
[0105] The magnet connecting member 74 which is formed in a
substantially square frame shape is fixed to upper faces of the
four drive magnets 68 and the magnet connecting member 75 which is
formed in a substantially square frame shape is fixed to under
faces of the four drive magnets 68. The magnet connecting members
74 and 75 are formed of a stainless-steel plate. A nickel plating
layer consisting of nickel or nickel alloy consisting mainly of
nickel is formed on the surfaces of the magnet connecting members
74 and 75.
[0106] In this embodiment, the drive magnets 68 and the magnet
connecting member 74 are joined to each other by joining layers 76
consisting of tin-based metal containing at least tin. Similarly,
the drive magnets 68 and the magnet connecting member 75 are joined
to each other by joining layers 77 consisting of tin-based metal
containing at least tin. In other words, as shown in FIGS. 10 and
13, the drive magnets 68 and the magnet connecting member 74 are
joined to each other by the joining layers 76 which are disposed
between the under face of the magnet connecting member 74 and the
upper faces of the drive magnets 68. Further, the drive magnets 68
and the magnet connecting member 75 are joined to each other by the
joining layers 77 which are disposed between the upper face of the
magnet connecting member 75 and the under faces of the drive
magnets 68. The joining layers 76 and 77 are structured of tin, tin
alloy containing copper, tin alloy containing gold, tin alloy
containing silver, tin alloy containing bismuth or the like.
[0107] The magnet connecting members 74 and 75 in this embodiment
are a metal member which is fixed to the drive magnets 68. Further,
one of the magnet connecting members 74 and 75 is a first metal
member and the other of the magnet connecting members 74 and 75 is
a second metal member.
[0108] The four drive magnets 68 are fixed to the respective four
outer side faces structuring the outer peripheral face of the
camera module 52 and are disposed on an inner peripheral side of
the case body 62 with respect to the drive coils 67. In this
embodiment, after the four drive magnets 68 and the magnet
connecting members 74 and 75 have been joined to each other and the
four drive magnets 68 have been connected with each other by the
magnet connecting members 74 and 75, the four drive magnets 68 are
fixed to the outer side face of the camera module 52.
[0109] The magnet piece 72 is magnetized so that a magnetic pole
formed on one side face and a magnetic pole formed on the other
side face are different from each other. In other words, the magnet
pieces 72 are magnetized so that the magnetic poles formed on the
front, rear, right and left inner side faces which are fixed to the
camera module 52 are different from the magnetic poles formed on
the front, rear, right and left outer side faces which face the
drive coils 67. Similarly, the magnet pieces 73 are magnetized so
that the magnetic poles formed on the front, rear, right and left
inner side faces which are fixed to the camera module 52 are
different from the magnetic poles formed on the front, rear, right
and left outer side faces which face the drive coils 67. Further,
the magnet pieces 72 and 73 are magnetized so that the magnetic
pole of the inner side face of the magnet piece 72 is different
from the magnetic pole of the inner side face of the magnet piece
73. In other words, the magnet pieces 72 and 73 are magnetized so
that the magnetic pole of the outer side face of the magnet piece
72 is different from the magnetic pole of the outer side face of
the magnet piece 73.
[0110] As described above, the drive coils 67 are disposed along
the inner peripheral face of the case body 62 and, as shown in FIG.
14, are disposed in gap spaces between the drive magnets 68 fixed
to the outer side face of the camera module 52 and the inner
peripheral face of the case body 62. In other words, the drive
coils 67 face the drive magnets 68 through predetermined gap spaces
in the front and rear direction or in the right and left direction.
Further, the drive coils 67 also face the joining layers 76 and 77
through predetermined gap spaces in the front and rear direction or
in the right and left direction (see FIG. 10).
[0111] A plate spring 54 is provided with a movable side fixed part
which is fixed to the magnet connecting member 75, a fixed side
fixed part which is fixed to the fixed body 53, and a plurality of
spring parts which connect the movable side fixed part with the
fixed side fixed part. In this embodiment, the camera module 52
which is fixed to the movable side fixed part through the magnet
connecting member 75, the drive magnets 68 and the like is capable
of being swung by resiliently bending of the spring parts with
respect to the fixed side fixed part. Further, the plate spring 54
is fixed in a resiliently bent state so that the upper end of the
spherical member 64 and the abutting plate 59 are surely abutted
with each other and so that pressurization is generated for surely
abutting the lower end side of the spherical member 64 with an edge
of the arrangement hole 63c of the lower case body 63 (in other
words, so that an urging force for urging the camera module 52 to
the lower direction is generated).
[0112] In the optical device 51 structured as described above, when
a variation of inclination of the camera module 52 is detected by a
gyroscope which is mounted on the board 57, an electric current is
supplied to the drive coils 67 based on a detection result of the
gyroscope. When an electric current is supplied to the drive coils
67, the camera module 52 is swung so that the optical axis "L" is
inclined with the supporting point part 65 as a swing center around
the front and rear direction and/or around the right and left
direction to correct a shake.
[0113] A surface of the drive magnet 68 before joined to the magnet
connecting members 74 and 75 is formed with a tin plating layer
which becomes the joining layers 76 and 77 after having been joined
so as to cover the nickel plating layer. Further, the drive magnet
68 is not magnetized before joined to the magnet connecting members
74 and 75. In this embodiment, a tin plating layer is not formed so
as to cover the nickel plating layer on the surfaces of the magnet
connecting members 74 and 75 before joined to the drive magnet 68.
However, a tin plating layer may be formed so as to cover the
nickel plating layer on the surfaces of the magnet connecting
members 74 and 75.
[0114] When the drive magnets 68 and the magnet connecting members
74 and 75 are to be joined to each other, first, the drive magnets
68 and the magnet connecting members 74 and 75 are set in a joining
jig in a state that the four drive magnets 68 are sandwiched
between the magnet connecting member 74 and the magnet connecting
member 75. After that, the drive magnets 68 and the magnet
connecting members 74 and 75 are disposed in an induction coil.
Further, an electric current is supplied to the induction coil
while pressurizing and holding so that the drive magnets 68 and the
magnet connecting member 74 are tightly contacted with each other
and the drive magnets 68 and the magnet connecting member 75 are
tightly contacted with each other. When the electric current is
supplied to the induction coil, the drive magnets 68 and the magnet
connecting members 74 and 75 are heated by eddy currents generated
in the drive magnets 68 and the magnet connecting members 74 and 75
and thus, the tin plating layers on the surfaces of the drive
magnets 68 are melted. Further, when the supply of the electric
current to the induction coil is stopped, the melted tin-based
metal is solidified to form the joining layers 76 and 77 and thus,
the drive magnets 68 and the magnet connecting members 74 and 75
are joined to each other by the joining layers 76 and 77. In this
embodiment, after the drive magnets 68 and the magnet connecting
members 74 and 75 have been joined to each other, the four drive
magnets 68 are simultaneously magnetized. Further, at the time of
induction heating, the drive magnets 68 and the magnet connecting
members 74 and 75 are heated to about 230.degree. C. (degree
C.)-300.degree. C. (degree C.).
[0115] As described above, in this embodiment, the drive magnets 68
and the magnet connecting members 74 and 75 are joined to each
other by the joining layers 76 and 77 which are formed so that the
tin plating layer on the surface of the drive magnet 68 before
joined to the magnet connecting members 74 and 75 are melted and
solidified. Therefore, the joining layers 76 and 77 are not
protruded from portions between the drive magnet 68 and the magnet
connecting members 74 and 75. Accordingly, in this embodiment, even
when a gap space between the drive magnet 68 and the drive coil 67
is set to be narrow in order to prevent a drive force from being
lowered due to downsizing of the drive magnet 68 and the drive coil
67, the gap space between the drive magnet 68, the joining layers
76 and 77 and the drive coil 67 is formed with a high degree of
accuracy. As a result, an interference of the camera module 52 with
the fixed body 53 is prevented. In other words, in this embodiment,
even when the size of the optical device 51 is reduced by reducing
the sizes of the drive magnet 68 and the drive coil 67 and by
narrowing a gap space between the drive magnet 13 and the drive
coil 14, an interference of the camera module 52 with the fixed
body 53 is prevented and the camera module 52 is swung
appropriately.
[0116] In this embodiment, the tin plating layer which is formed on
the surface of the drive magnet 68 before joined to the magnet
connecting members 74 and 75 is melted by induction heating. In
other words, in this embodiment, the drive magnets 68 and the
magnet connecting members 74 and 75 are disposed in the induction
coil and an electric current is supplied to the induction coil to
melt the tin plating layer. Therefore, temperatures of the drive
magnets 68 and the magnet connecting members 74 and 75 when the tin
plating layers are to be melted are made uniform and thus variation
of a joining strength of the drive magnet 68 to the magnet
connecting member 74 and variation of a joining strength of the
drive magnet 68 to the magnet connecting member 75 can be
prevented. Further, in this embodiment, the tin plating layers can
be melted without contacting the drive magnets 68 and the magnet
connecting members 74 and 75 with the induction coil. Therefore,
relative positional displacement of the drive magnets 68 and the
magnet connecting members 74 and 75 from each other is prevented
when the tin plating layers are to be melted.
[0117] In this embodiment, in a state that the drive magnet 68 is
sandwiched between the magnet connecting members 74 and 75, the tin
plating layer on the surface of the drive magnet 68 is melted and
solidified to form the joining layers 76 and 77. Therefore, the
drive magnets 68 and the magnet connecting members 74 and 75 are
fixed to each other by one operation. Accordingly, in this
embodiment, a fixing operation of the drive magnets 68 to the
magnet connecting members 74 and 75 is easily performed.
[0118] In the second embodiment, the magnet connecting member 74
and the magnet connecting member 75 are fixed to the drive magnet
68. However, the present invention is not limited to this
embodiment. For example, only one of the magnet connecting member
74 and the magnet connecting member 75 may be fixed to the drive
magnet 68.
[0119] In the second embodiment, the optical device 51 is provided
with an autofocus function but the optical device 51 may be
provided with no autofocus function. In other words, the camera
module 52 is not required to provide with the lens drive
mechanism.
[0120] In the second embodiment, the optical device 51 is formed so
that its shape when viewed in the optical axis direction is a
substantially square shape. However, the optical device 51 may be
formed so that its shape when viewed in the optical axis direction
is a roughly rectangular shape. Further, the optical device 51 may
be formed so that its shape when viewed in the optical axis
direction is a roughly polygonal shape other than a rectangular
shape or its shape when viewed in the optical axis direction is a
circular shape or an elliptic shape.
[0121] Although the present invention has been shown and described
with reference to the specific embodiments, various changes and
modifications will be apparent to those skilled in the art from the
teachings herein.
[0122] In the first embodiment, the tin plating layer on the
surface of the drive magnet 13 are melted and solidified in a state
that the drive magnet 13 is sandwiched between the cover member 10
and the magnetic member connecting body 21 and, in this manner, the
cover member 10, the drive magnet 13 and the magnetic member
connecting body 21 are simultaneously joined to each other.
However, the present invention is not limited to this embodiment.
For example, it may be structured that, first, the cover member 10
and the drive magnet 13 are joined to each other and, after that,
the drive magnet 13 and the magnetic member connecting body 21 are
joined to each other. Similarly, in the second embodiment, the tin
plating layer on the surface of the drive magnet 68 are melted and
solidified in a state that the drive magnet 68 is sandwiched
between the magnet connecting member 74 and the magnet connecting
member 75 and, in this manner, the drive magnet 68 and the magnet
connecting members 74 and 75 are simultaneously joined to each
other. However, it may be structured that, first, the drive magnet
68 and the magnet connecting member 74 are joined to each other
and, after that, the drive magnet 68 and the magnet connecting
member 75 are joined to each other.
[0123] In the first embodiment, when the cover member 10, the drive
magnets 13 and the magnetic members 17 are to be joined to each
other, the tin plating layers formed on the surfaces of the drive
magnets 13 are melted by induction heating. However, the present
invention is not limited to this embodiment. For example, it may be
structured that, when the cover member 10, the drive magnets 13 and
the magnetic members 17 are to be joined to each other, heater
chips are abutted with the cover member 10, the magnetic members 17
and the like, the tin plating layers formed on the surfaces of the
drive magnets 13 are melted. Alternatively, it may be structured
that a laser beam is irradiated to boundary parts between the cover
member 10 and the drive magnets 13 and to boundary parts between
the drive magnets 13 and the magnetic members 17 and, in this
manner, the tin plating layers formed on the surfaces of the drive
magnets 13 are melted.
[0124] Similarly, in the second embodiment, when the drive magnets
68 and the magnet connecting members 74 and 75 are to be joined to
each other, the tin plating layers formed on the surfaces of the
drive magnets 68 are melted by induction heating. However, it may
be structured that heater chips are abutted with the magnet
connecting members 74 and 75 and the like, the tin plating layers
formed on the surfaces of the drive magnets 68 are melted.
Alternatively, it may be structured that a laser beam is irradiated
to boundary parts between the drive magnets 68 and the magnet
connecting member 74 and to boundary parts between the drive
magnets 68 and the magnet connecting member 75 and, in this manner,
the tin plating layers formed on the surfaces of the drive magnets
68 are melted.
[0125] While the description above refers to particular embodiments
of the present invention, it will be understood that many
modifications may be made without departing from the spirit
thereof. The accompanying claims are intended to cover such
modifications as would fall within the true scope and spirit of the
present invention.
[0126] The presently disclosed embodiments are therefore to be
considered in all respects as illustrative and not restrictive, the
scope of the invention being indicated by the appended claims,
rather than the foregoing description, and all changes which come
within the meaning and range of equivalency of the claims are
therefore intended to be embraced therein.
* * * * *